眶腔通道的CT三维重建及临床意义

目的　为眶腔及其周围区域病变相互蔓延的临床诊断提供解剖学依据。 方法　选取头部无眶腔及眶腔通道病变者100例，在螺旋CT机上以眶耳线（CML）为基线连续扫描，将原始影像数据输入CT三维重建工作站，沿各眶腔通道长轴和垂直于各通道长轴分别进行CT图像重建。观察眶腔通道的位置、形态及毗邻结构，测量其径线。 结果　眶腔通道的骨性鼻泪管、眶下管、眶下裂、眶上裂和视神经管的长度（或长径）分别为（13.72±1.56）、（24.62±2.03）、（28.16±1.03）、（19.02±2.43）和（6.20±0.44）mm。男、女性骨性鼻泪管的长度和左右径有显著性差异（P<0.05），男性骨性鼻泪管的长度大于女性，女性骨性鼻泪管的左右径均大于男性。视神经管眶口、中部和颅口的面积分别为（25.22±4.89）、（18.72±3.79）和（24.88±4.23）mm2，视神经管中部的面积最小，是视神经管狭窄的好发部位。 结论　CT三维重建可直观地显示眶腔通道的微细结构，对眶腔及其周围区域恶性肿瘤、炎症等相互蔓延的影像诊断具有重要的临床意义。

Three-dimensional CT reconstruction of the orbital cavity channel and its clinical significance

Objective　To provide anatomical basis for clinical diagnosis of lesion spread between the orbital cavity and its surrounding area. 　Methods　100 cadaveric heads were selected with no diseases of the orbital cavity and the orbital cavity channel, and scanned in series by spiral CT from canthomeatal line (CML)； all original images were transferred to the CT three-dimensional reconstruction workstation, and the orbital cavity channel were reconstructed through its long axis and perpendicular to the long axis. The position, shape and its adjacent structures of orbital cavity channel were observed and measured for diameter. Results　The length or longidudinal diameter of bony nasolacrimal duct, infraorbital canal, inferior orbital fissure, superior orbital fissure and optic canal in CT image were (13.72±1.56), (24.62±2.03), (28.16±1.03), (19.02±2.43) and (6.20±0.44) mm respectively. There were significant difference in the length and transverse diameter between bony nasolacrimal duct of the male and female (P<0.05), the length and transverse diameter of bony nasolacrimal duct were larger in male than in female. The size of the orbital opening, middle part and cranial opening of the optic canal was (25.22±4.89), (18.72±3.79) and (24.88±4.23) mm2 respectively. It was narrowest in the middle part of optic canal, which was the frequent location of optic canal stenosis. Conclusion CT three-dimensional reconstruction could display micro-structure of the orbital cavity channel intuitively, making it an important tool for diagnosis of the malignant tumor and inflammation of orbital cavity and its surrounding area.